New Malaria Vaccine 100% Effective, But May Be Difficult to Scale

Today, a human trial for a malaria vaccine reported up to 100% protection for ten weeks following the last dose, a potential breakthrough for a vexing disease.

While this vaccine has been trialed before, it has never been this effective. The key appears to be how the vaccine was delivered—directly into the bloodstream as opposed to into a muscle, as most vaccines are.

The trial consisted of 35 participants who had never been exposed to malaria. They were first injected with varying doses of the vaccine, which uses weakened malaria-causing parasites Plasmodium falciparum, along with chloroquine, an antimalarial drug. Participants were then infected with the same strain of malaria used in the vaccine. The results were published today in the journal Nature.

“I think it’s among some of the best malaria protection data,” said Dan Barouch, a professor of medicine at Harvard Medical School, “but we have to keep in mind it is in a controlled human challenge study. So, whether it can be extrapolated for protection against malaria in the field remains to be determined.”